COLREGs Rule 28: Constrained by draught

Part of the convention Lights and shapes

In addition to the lights of a power-driven vessel she may show three all-round reds in a vertical line, or a cylinder by day. It is a warning: I have no water to turn into.

At sea it looks like this

Three reds in a line on the approach to a port is a loaded tanker in the channel. Under rule 18 every vessel except those not under command or restricted in ability to manoeuvre must avoid impeding her.

The rule says«A vessel constrained by her draught may, in addition to the lights prescribed for power-driven vessels in Rule 23, exhibit where they can best be seen three all-round red lights in a vertical line, or a cylinder».

Lights and shapes for this rule

Rule 28

Constrained by her draught

seen from ahead (her starboard side on your left)

seen from her starboard beam

seen from astern

In addition to the lights of a power-driven vessel she may show three all-round red lights in a vertical line, or a cylinder by day.

Set: Masthead lights, sidelights, sternlight plus three all-round reds. Cylinder by day.
Tell: Three reds in a column together with masthead lights: depth will not let her turn. Two reds without masthead lights would mean a breakdown.
Priority: Every vessel except those not under command or restricted in ability to manoeuvre must avoid impeding her safe passage.
In fog: One prolonged and two short blasts.

By day: cylinder

Check yourself

Who is this?

seen from ahead (her starboard side on your left)

seen from her starboard beam

seen from astern

A vessel constrained by her draught: three all-round reds together with the lights of a power-driven vessel. A cylinder by day.

Rule 28.

What does a cylinder mean?

By day

A vessel constrained by her draught: the daytime equivalent of three all-round reds.